Improvement in indicators for mining-shafts



C. 0. RICHARDSON. mmcnons FOR MINING-SHAFTS. No. 193,462, 'Patsnted July 24,1877;

mvmon @MW/a monusvs UNITED STATES PATENT OFFICE.

CALVIN O. RICHARDSON, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT IN INDICATORS FOR MlNlNG-SHAFTS.

Specification forming part of Letters Patent No. 193,462, dated July 24, 1877; application filed June 11, 1877.

To all whom it may concern:

Be it known that I, CALVIN O. RICHARD- SON, of the city and county of San Francisco and State of California, have invented a new and Improved Indicator for Mining-Shafts, of which the following is a specification :-v

Figure 1 is a side elevation of my improved indicator, and Fig. 2 is a front view.

Similar letters of reference indicate corresponding parts.

In the drawing, a is a bar to which the hell I) is bolted in a horizontal position. C is the clapper of the bell, which is supported by a spring shank or arm, h, which permits the clapper to vibrate freely when the bell is moved.

The bar a is fastened to the hoisting-rope A of the mining-shaft by means of clips or by lashing it with cords.

My invention consists of a bell having a spring tongue or clapper that vibrates easily,

so that when the bell is attached to the hoisting-rope of a mining-shaft, and the tub or cage descending, the clapper will strike the bell when there is a slight checking or variation in speed, which is caused by the momentum of the clapper overcoming the slight resistance of the spring-tongue. given of the descent of the cage or tub. A more violent ringing is caused as the tub approaches the bottom, by the brakesman' making a few sudden pressures upon the brake, thus warning the workmen to stand from under.

Having thus described my invention, 1 claim as new and desire to secure by Letters Patent- The bell b, secured to the bar a, and containing the spring-clapper C, combined with a hoisting-rope, substantially as and for the purpose herein shown and described.

Witnesses: E. H. THARP, JOHN F. MYERS.

Thus warning is' 

